HP 8753E Service Manual page 114

The HP 8496A step attenuator (Option 001, H18) comes with a
special calibration that supports the measurement uncertainties
expressed in the test record for this performance test.
The special calibration consists of two measurements The hrst
is a measurement of the attenuation at each step. The data
reported for this measurement have the following uncertainties:
n
n
n
The second calibration measurement characterizes match
stability between attenuator settings for each attenuator port.
The vector difference of S11 or ($2) between the reference
attenuation step and all the other steps is measured. The
magnitude of this difference is certified to be ~0.0316 (>30 dB).
The HP 8496A used for this test wiU have known attenuator
errors for attenuations up to 100 dB using a test frequency of
30 MHz. The attenuation used as a reference is 0 dB. If the
available calibration data is not expressed as attenuation errors,
it can be converted to such a form by the following equation:
(actual attenuation) - (expected attenuation) = attenuator error
Actual attenuation values that are greater than the expected
attenuation values wiII result in positive errors Actual
attenuation values that are less than the expected attenuation
values wiII resuh in negative errors.
System Veriiication and
Performance Tests